1. Field of the Invention
The present invention relates to a disc player and, more particularly, to a disc player which can reproduce information recorded in discs such as compact discs (CDs) and DVDs (Digital Versatile Discs).
2. Description of the Relevant Art
FIG. 26 is a sectional side view schematically showing the construction of a mobile disc player having an autochanger function disclosed in Japanese Kokai No. 2000-48462. A housing 51 constituting a disc player 50 comprises a main chassis 52. At the front of the disc player 50, a front panel 54 with a disc insert/eject slot 54a for insertion and ejection of a disc 53 formed thereon is mounted.
Above the forward portion of the main chassis 52, a mount chassis 60, which can be displaced up and down by engagement thereof with turntable lifting slide plates (not shown) slidably mounted on the sidewalls of the main chassis 52, is arranged.
On the mount chassis 60, a floating chassis 62 is arranged through a floating mechanism 61 comprising a locking member 61a, a locking shaft 61b and spring parts 61c. With the floating mechanism 61, the influence of vibration or shock applied from the outside during reproduction can be reduced.
On the floating chassis 62, a slide chassis 63 is mounted in such a manner as to be slidable in a back-and-forth direction relative to the floating chassis 62. On the slide chassis 63, a swing board 66 swingable in an arc, on which a turntable unit 64 having a turntable 64a, and a pickup unit (hereinafter, referred to as a PU unit) 65 are mounted, is placed.
Above the swing board 66, an insert/eject mechanism 73 comprising a disc supporting plate 70 for supporting the disc 53, an insert/eject roller 71 for moving the disc 53 supported by the disc supporting plate 70 backward and forward, and a shutter section 72 whereby the disc insert/eject slot 54a is opened or closed, are arranged. With the insert/eject mechanism 73, the insertion/ejection operation of the disc 53 can be conducted.
At prescribed places in the rearward portion of the main chassis 52, a couple of lifting guides 55 are vertically mounted. On the main chassis 52, a stocker bottom board 80, six stockers 81 for setting discs 53 thereon, and a stocker top board 82 for retaining the surface of a disc 53 set on the uppermost stocker 81 in ascending order, are laminated with the lifting guides 55 inserted through insertion holes (not shown) arranged in each of them.
The stocker bottom board 80 is in engagement with lifting slide plates 56 slidably mounted on the sidewalls of the main chassis 52 in a manner whereby it moves up and down with the movement of the lifting slide plates 56.
The stockers 81 are in engagement with division slide plates 57 slidably mounted on the sidewalls of the main chassis 52 in a manner whereby they are divided into the upper and lower parts with the movement of the division slide plates 57. In insertion, ejection, reproduction or the like of a disc 53, a prescribed space is formed by the division so that the PU unit 65 can approach the disc 53. Drive motors (not shown) as driving forces for slidably driving these turntable lifting slide plates, lifting slide plates 56 and division slide plates 57 are arranged in two corners of the rear of the main chassis 52.
On both side portions of the stocker top board 82, hooks (not shown) for hooking coil springs (not shown) are formed. One end of a slender coil spring is caught with the hook, while the other end thereof is caught with a hook (not shown) arranged near the center of the stocker bottom board 80. With these coil springs, the overall stockers 81 are energized for being closer, even if the stockers 81 are under divided conditions or all of them are set close.
A control circuit 90, conducting driving control of each section, which is mounted on a substrate, is arranged on the outside wall of the main chassis 52.
FIG. 27 comprises diagrams schematically showing the construction of the stocker 81, wherein FIG. 27(a) is a perspective view, while FIG. 27(b) is an enlarged fragmentary view showing an antifloating claw.
The stocker 81 comprises a periphery 81a formed in the shape of an almost semicircular arc so as to surround the outer regions of a disc 53, and a narrow disc receiver 81b for supporting the outer regions of the disc 53. In the rear portion of the periphery 81a, antifloating claws 81c for preventing the disc 53 set on the disc receiver 81b from floating upward are formed. The antifloating claw 81c is formed so as to be inwardly convex from the inner wall surface of the periphery 81a with a claw portion 81e having a slightly tapered plane 81d formed thereon.
In both side portions of the periphery 81a, division projections 81f for lifting/division by engagement with the division slide plates 57, and a couple of insertion holes 81g for inserting the lifting guides 55 therethrough are formed. In both end portions of the periphery 81a, dislocation preventive projections 81h for preventing the dislocation of the stockers 81 when they are put in piles are formed.
The main operation of the conventional disc player 50 is described below.
FIG. 28 comprises simplified side views showing the operation of the conventional disc player 50, which illustrate the insertion operation of a disc 53.
FIG. 28(a) shows an insertion standby state where the disc 53 can be inserted. With the insert/eject roller 71 being lowered, the insert/eject mechanism 73 is in a state of being capable of pulling in the disc 53 to be inserted.
When the fifth stocker 81 from the bottom (hereinafter, referred to as the fifth stocker) is selected as a stocker on which the disc 53 is set, the first to fourth stockers 81 are kept close, while the fifth stocker is caused to ascend so that the turntable unit 64 can enter between the fourth and fifth stockers.
The upper stocker thereabove (the sixth stocker in this case) is caused to move further upward so that the disc 53 can be carried into the space between the selected fifth stocker and the sixth stocker. The turntable unit 64 is on standby at a prescribed standby position in order to hold the inserted disc 53 on the turntable 64a and carry it to the stocker 81 side.
FIG. 28(b) shows a state where one disc 53 is inserted in the disc insert/eject slot 54a. The insert/eject roller 71 of the insert/eject mechanism 73 is driven to once pull the inserted disc 53 into the interior of the system, and then the shutter section 72 is closed (FIG. 28(c)).
Then, the disc 53 is conveyed in the reverse direction and the positioning thereof is conducted at a place where it is brought into engagement with the shutter section 72 (FIG. 28(d)). To the disc 53 located in FIG. 28(d), the turntable unit 64 is caused to ascend, and the disc 53 is placed on the turntable 64a. By operating a catching mechanism (not shown) of the turntable unit 64, the disc 53 is clamped to the turntable 64a (FIG. 28(e)).
By sliding the slide chassis 63 to the stocker 81 side, the turntable unit 64 is horizontally moved so as to pull the disc 53 out of the insert/eject mechanism 73 and move it between the fifth and sixth stockers 81 (FIG. 28(f)). After moving the disc 53 to the reproduction position, the locking shaft 61b fixed with the locking member 61a is released, so that the turntable unit 64 is made in a state of mechanically floating with the floating mechanism 61. The turntable 64a is rotatably driven so as to reproduce the disc 53 (FIG. 28(g)).
FIG. 29 comprises simplified side views for illustrating the changing operation of a disc to be reproduced of the conventional disc player 50.
FIG. 29(a) shows a state of reproducing the fifth disc 53 from the bottom in the similar condition to that of FIG. 28(g). When the user gives a command to reproduce the fourth disc 53 in this state, the locking shaft 61b is fixed with the locking member 61a, so that the floating state of the turntable unit 64 is cleared. The turntable lifting slide plates and the division slide plates 57 are caused to slide, the turntable unit 64 and the fifth stocker 81 on which the disc 53 was previously set are caused to rise, and the disc 53 is set on the disc receiver 81b of the fifth stocker 81.
The catching mechanism of the turntable unit 64 is activated so as to clear the state of clamping the disc 53 (FIG. 29(c)). Then, the turntable unit 64 is moved downward and the disc 53 is taken from the turntable 64a onto the fifth stocker 81 (FIG. 29(d)).
The turntable unit 64 is horizontally moved to under the insert/eject mechanism 73 (FIG. 29(e)), and then, all the divided stockers 81 are caused to descend, so that all the stockers 81 are piled up, resulting in reset of the divided state (FIG. 29(f)).
In the state of all the stockers 81 in piles, the stockers 81 are divided into the upper part including the selected fourth stocker 81 and the stockers 81 thereabove, and the lower part constituted of the stockers 81 below the selected fourth stocker 81 (FIG. 29(g)). The turntable unit 64 is moved into the space between the third and fourth stockers 81 (FIG. 29(h)).
The turntable unit 64 is moved upward, a disc 53 to be reproduced is placed on the turntable 64a, and the catching mechanism of the turntable unit 64 is activated so as to clamp the disc 53 (FIG. 29(i)). Then, the locking shaft 61b fixed with the locking member 61a is released so as to make the turntable unit 64 in a mechanically floating state, the fourth stocker 81 on which the disc 53 was previously set is moved downward, and the reproduction of the selected fourth disc 53 is started (FIG. 29(j).
When the user carelessly inserts two discs 53 successively in the insertion of the disc 53 shown in FIG. 28(b), the conventional disc player 50 senses the successive insertion and tries to eject the second disc 53 by fail-safe function. However, if the user tries to push in the second disc 53 further against the ejecting operation, the first disc 53 previously inserted is pushed forward from its positioned place. In this case, the disc 53 cannot be placed on the turntable 64a on standby at the prescribed standby position shown in FIG. 28(d), and moreover, the disc 53 falls to the stocker 81 side.
In the conventional disc player 50, since the thus fallen disc 53 widely moves in the unoccupied space inside the system, the fallen disc 53 cannot be placed on the turntable 64a again. As a result, the disc 53 is held in a dislocated state from the stocker 81 and cannot be ejected through the disc insert/eject slot 54a. 
If the disc 53 is held in the dislocated state from the stocker 81, the disc player 50 recognizes that no disc 53 is set on the stocker 81. Therefore, when the next disc 53 is inserted, an attempt to set the disc 53 again on the stocker 81 with the disc 53 dislocated therefrom is made. As a result, two discs are stacked, so that the system gets clogged with them so as to become inoperable.
In the conventional disc player 50, when vibration or shock stronger than the allowable values is applied thereto during the disc reproduction shown in FIG. 28(g) or FIG. 29(j), the disc 53 set on the top stocker 81 of the lower part (the fourth from the bottom in FIG. 28(g), while the third from the bottom in FIG. 29(j)) is sometimes dislocated from the stocker 81.
However, in the conventional disc player 50, once the disc 53 is dislocated from the stocker 81, it widely moves inside the system as it is in the dislocated state, and it is impossible to return the disc 53 to its original normal position. Therefore, the disc 53 cannot be placed on the turntable 64a, and the disc 53 dislocated from the stocker 81 cannot be ejected through the disc insert/eject slot 54a, similarly to the above case.
In the conventional disc player 50, when strong vibration or shock is applied thereto during the dividing operation of the stockers 81 (the operation proceeding from FIG. 29(f) to FIG. 29(g)) in changing of the disc 53 to be reproduced and the like, the locations of the division projections 81f in the right and left side portions of the stocker 81 in engagement with the division slide plates 57 sometimes become different from each other. As a result, the stocker 81 gets inclined and the dividing operation is interrupted, so that the system becomes inoperable.
When thus failing to divide the stockers 81, the disc 53 is dislocated from the stocker 81 and falls out of the stocker 81, so that it cannot be ejected through the disc insert/eject slot 54a, similarly to the above cases.
In cases where the disc 53 cannot be taken out, or in cases where the system becomes inoperable, troublesome activities of removing the disc player 50 from the vehicle, disassembling it, taking out the disc 53 blocking inside the system, reassembling the disc player 50, and mounting it on the vehicle, must be conducted.